61005551111 has 4 divisors (see below), whose sum is σ = 62493491424. Its totient is φ = 59517610800.

The previous prime is 61005551051. The next prime is 61005551153. The reversal of 61005551111 is 11115550016.

61005551111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61005551111 - 2²² = 61001356807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61005551171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 743970095 + ... + 743970176.

It is an arithmetic number, because the mean of its divisors is an integer number (15623372856).

Almost surely, 2^61005551111 is an apocalyptic number.

61005551111 is a deficient number, since it is larger than the sum of its proper divisors (1487940313).

61005551111 is a wasteful number, since it uses less digits than its factorization.

61005551111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1487940312.

The product of its (nonzero) digits is 750, while the sum is 26.

It can be divided in two parts, 610055 and 51111, that added together give a palindrome (661166).

The spelling of 61005551111 in words is "sixty-one billion, five million, five hundred fifty-one thousand, one hundred eleven".